The present invention is directed to the fields of tap driving, drilling, and the like, and particularly to machining processes which require the use of coolants or lubricants on the tool.
The use of cooling and lubrcating liquids such as sulfur based oils, synthetics, and the like, in machining operations such as tapping and drilling are well known. The coolant or lubricant must be disposed at the interface of the tool and the metal in order to be effective.
Unfortunately, the prior art techniques for providing the lubricant or coolant at the appropriate locations have been made difficult in many applications due to inaccessibility of the machined surface to the source of the coolant or lubricating fluid. One solution to the problem of inaccessibility in the field of tap driving has been to provide a tap driver having a central bore through which the coolant is passed. The tap which is attached to the tap driver is also provided with an internal bore and output ports through which the coolant may travel and exit. However, taps, as well as other tools, such as drills and the like, are typically not provided with the central bore and output ports as required for the above-described operation. Providing the tool with the requisite bore and output ports is an exceedingly expensive and time consuming operation and further causes a weakening of the tool.
To further complicate matters, the above-described inaccessibility of certain machined surfaces upon which the tools act, many times requires the use of an extended tool driver which must be of limited diameter so that the tool driver can extend through small openings in a particular structure to reach the surface to be machined. This can cause problems where an extended driver, such as an extended "tension/compression" tap driver must be employed, due to the hardware, such as tension and compression springs, seals, and the like, which must be incorporated into the tap driver. The limited diameter allowable on such a tap driver places a severe constraint on the ability of a tap driver to provide such tension and compression functions.